Process for the production of insulating paper containing phenol resins



mama May 31, 1927.

UNITED STATES ATENT FFiCE.

CARL AUGUST HAANEN, OF GOLOGNE- GERMANY, ASSIGNOR TO FELTEN &

GUILLEAUHE GABLSWEBK ACTEN-GESELLBCEAI'T, F COLOGNE-MULHEIM, GER- PBOOESS FOR THE PRODUCTION OF INSULATING PAPER CONTAINING PHENOL RESINS.

No Drawing. Application filed November 27, 1986, Serial No. 151,260, and in Germany April 28, 1926.

It is known to produce insulating paper, more particularly hard paper, by saturating the finished aper with solutions of phenol resins and subsequently hardening the resins.

The object of the present invention is a process for the production of insulating paper containing phenol resin.

e process is as follows The water of pulps of fibrous material of any 'kind is first of all replaced in a suitable manner, for instance in displacing a paratus, by a solvent for phenol resins, or instance alcohol. Solutions containing phenol resins are added to the mass obtained in this is manner and by introducing the well mixed mass into water, the phenol resin is precipitated in and on the fibre. The resin contained in the fibre can be left as it is or converted by heat into the C-state, according to the working up processes employed and the purposes in view. The resulting paper pprlp is used for the manufacture of paper or d paper as well as, after drying, for the prouction of pressed articles. The papers produced according to the process according to the invention can be successfully used as insulation for high tension cables, the gradin according to the dielectric constants, desirable therefor being obtained by the difierent percentage .content of phenol res'n in the various Layers of paper.

What I claim is:- 1. .A process for the production of insulating paper containing phenol resins, consistlng in replacing the water in the fibrous 85 pulp by solvents for phenol resins, adding solutions containing phenol resins, preci itating the phenol resin in and upon t e fibres by the addition of water and working up the fibrous material to form paper and 40 pressed articles.

2. A process for the production of vinsulating paper containing phenol resins, consistin in replacing the water in the fibrous pulp y solvents for phenol resins, adding solutions containing phenol resins, precipitating the phenol resin in and upon the fibres by the addition of water, converting the resin into the C-state by the action of heat and working up the fibrous material to formgaper and pressed articles.

3. process for the production of insulating paper containing phenol resins, consisting in replacing the water in the fibrous pulp by solvents for phenol resins, adding solutions containing phenol resins, precipitating the phenol resin in and. upon the fibres by the addition of water, working up the fibrous material to form paper and pressed articles and converting the resin into the C-state in the said finished paper and pressed articles.

In twtimony whereof I have signed my name to this specification.

GARL AUGUST HAANEN 

